<template>
  <div class="upload-file">
    <el-upload :action="uploadFileUrl" :before-upload="handleBeforeUpload" :file-list="fileList" :limit="limit"
               :on-error="handleUploadError" :on-exceed="handleExceed" :on-success="handleUploadSuccess"
               :show-file-list="false" :headers="headers" class="upload-file-uploader" ref="upload"
    >
      <!-- 上传按钮 -->
      <el-button v-no-more-click size="mini" type="primary" :loading="loading">选取文件</el-button>
      <!-- 上传提示 -->
      <div class="el-upload__tip" slot="tip" v-if="showTip">
        请上传
        <template v-if="fileSize"> 大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b></template>
        <template v-if="fileType"> 格式为 <b style="color: #f56c6c">{{ fileType.join('/') }}</b></template>
        的文件
      </div>
    </el-upload>

    <!-- 文件列表 -->
    <transition-group class="upload-file-list el-upload-list el-upload-list--text" name="el-fade-in-linear" tag="ul" v-if="isShowFileList">
      <li :key="file.uid" class="el-upload-list__item ele-upload-list__item-content" v-for="(file, index) in list">
        <el-link :href="file.url" :underline="false" target="_blank">
          <span class="el-icon-document"> {{ getFileName(file) }} </span>
        </el-link>
        <div class="ele-upload-list__item-content-action">
          <el-link :underline="false" @click="handleDelete(index)" type="danger">删除</el-link>
        </div>
      </li>
    </transition-group>
  </div>
</template>

<script>
import {getToken} from '@/utils/auth'

export default {
  props: {
    // 值
    value: [String, Object, Array],
    // 大小限制(MB)
    fileSize: {
      type: Number,
      default: 5
    },
    limit: {
      type: Number,
      default: 1
    },
    // 文件类型, 例如['png', 'jpg', 'jpeg']
    fileType: {
      type: Array,
      default: () => ['doc', 'xls', 'ppt', 'txt', 'pdf', 'zip', 'rar']
    },
    // 是否显示提示
    isShowTip: {
      type: Boolean,
      default: true
    },
    isShowFileList: {
      type: Boolean,
      default: true
    }
  },
  data() {
    return {
      loading: false,
      uploadFileUrl: this.getBaseUrl() + '/common/upload', // 上传的图片服务器地址
      headers: {
        Authorization: 'Bearer ' + getToken()
      },
      fileList: []
    }
  },
  computed: {
    // 是否显示提示
    showTip() {
      return this.isShowTip && (this.fileType || this.fileSize)
    },
    // 列表
    list() {
      let temp = 1
      if (this.value) {
        // 首先将值转为数组
        const list = Array.isArray(this.value) ? this.value : [this.value]
        // 然后将数组转为对象数组
        return list.map((item) => {
          if (typeof item === 'string') {
            item = {fileName: item, url: item}
          }
          if (!item.uid) {
            item.uid = item.uid || new Date().getTime() + temp++
          }
          return item
        })
      } else {
        this.fileList = []
        return this.fileList
      }
    }
  },
  methods: {
    // 上传前校检格式和大小
    handleBeforeUpload(file) {
      // 校检文件类型
      if (this.fileType) {
        let fileExtension = ''
        if (file.name.lastIndexOf('.') > -1) {
          fileExtension = file.name.slice(file.name.lastIndexOf('.') + 1)
        }
        const isTypeOk = this.fileType.some((type) => {
          if (file.type.indexOf(type) > -1) return true
          if (fileExtension && fileExtension.indexOf(type) > -1) return true
          return false
        })
        if (!isTypeOk) {
          this.$message.error(`文件格式不正确, 请上传${this.fileType.join('/')}格式文件!`)
          return false
        }
      }
      // 校检文件大小
      if (this.fileSize) {
        const isLt = file.size / 1024 / 1024 < this.fileSize
        if (!isLt) {
          this.$message.error(`上传文件大小不能超过 ${this.fileSize} MB!`)
          return false
        }
      }
      this.loading = true
      return true
    },
    // 文件个数超出
    handleExceed() {
      this.$message.error('只允许上传' + this.limit + '个文件')
    },
    // 上传失败
    handleUploadError(err) {
      this.loading = false
      this.$message.error('上传失败, 请重试')
    },
    // 上传成功回调
    handleUploadSuccess(res, file) {
      this.loading = false
      this.$message.success('上传成功')
      if (this.limit > 1) {
        let fileObj = {
          fileName: res.fileName,
          originalFileName: res.originalFileName,
          extension: res.extension,
          url: this.getBaseUrl() + res.fileName
        }
        this.fileList.push(fileObj)
        this.$emit('input', this.fileList)
      } else {
        this.$emit('input', this.getBaseUrl() + res.fileName)
      }
    },
    // 删除文件
    handleDelete(index) {
      this.fileList.splice(index, 1)
      this.$emit('input', this.fileList)
    },
    // 获取文件名称
    getFileName(file) {
      console.log(file)
      if (file.originalFileName) {
        return file.originalFileName
      } else {
        let name = file.fileName
        if (name) {
          if (name.lastIndexOf('/') > -1) {
            return name.slice(name.lastIndexOf('/') + 1).toLowerCase()
          } else {
            return ''
          }
        } else {
          return ''
        }

      }
    }
  },
  created() {
    this.fileList = this.list
  },
}
</script>

<style scoped lang="scss">
.upload-file-uploader {
  margin-bottom: 5px;
}

.upload-file-list .el-upload-list__item {
  border: 1px solid #e4e7ed;
  line-height: 2;
  margin-bottom: 10px;
  position: relative;
}

.upload-file-list .ele-upload-list__item-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: inherit;
}

.ele-upload-list__item-content-action .el-link {
  margin-right: 10px;
}
</style>
